Specifications include, but are not limited to: The furnished system shall include, at minimum, the following: o Furnish and install new 10-ton indoor air handling unit with economizer. Air handling unit shall include, at a minimum: MERV-8 pre-filter, DX cooling coil, variable speed fan (ECM or VFD). Air handling unit shall be installed in old boiler room adjacent to existing air handling unit AHU-3. Re-use existing ductwork as practical to limit shutdown of control tower HVAC system. Route condensate to existing floor drain. o Provide 10-ton split condensing unit to provide cooling for matched air handling unit. Lead circuit shall have modulating capacity control via digital scroll compressor, inverter-driven compressor, or similar. Furnish and install all associated refrigerant piping for each circuit, including required specialties. o Provide new roof-mounted intake hood on roof curb sized for full economizer operation. Intake velocity shall not exceed 450 FPM to prevent snow intake. o Provide relief fan connection to return ductwork near new air handling unit, controlled to building static pressure point to relieve pressure caused by free cooling sequence. Duct to new louver or roof-mounted relief hood. o Provide UV light downstream of cooling coil within air handling unit sized for associated coils and airflow rate. o Integrate new and existing HVAC equipment within this area into existing Distech controls system. Existing equipment includes (3) existing hot water coils, (1) existing toilet room convector, (1) existing toilet room fan. Provide wiring back from new controller(s) to existing controller within airport. o Furnish and install new retrofit VAVs within ductwork at each existing booster coil location (total of 3). o Rebalance grilles and diffusers to air quantities required for proper heating and cooling of each space. o Provide electric steam humidifier (Condair EL Series or approved equal) with associated distribution tube manifold assembly. Provide all associated piping and accessories. o Provide structural review for new rooftop equipment loads and new penetration(s) through existing roof structure. o Provide electrical demolition and new work to support HVAC equipment, including new air handling unit, condensing unit, steam humidifier, UV lighting system, and DDC controllers. o All equipment shall be installed at least 10’-0” from roof edge unless a permanent OSHA safety railing is installed. Maintain all fire rated construction. o Contractor shall provide allowances for crane, roof repair, electrical wiring, and all other required labor and equipment as required to provide a complete installation. Coordinate with Owner and FAA for crane use on site. All roof patching shall be done in accordance with roofing manufactures requirements to maintain any existing roofing warranties. o Upon completion of scope of work identified below, site clear existing air handling unit and associated ductwork, hangers, piping, and supports no longer in use. Owner has Right of First Refusal of all nonhazardous items prior to site clearing, including but not limited to, salvaged copper and other valuable construction waste. Items the owner wishes to salvage shall be removed and delivered to a site for storage as directed by the owner. o Provide air-side and water-side balancing for new and existing HVAC equipment serving the entire work area.
